It is well known from Wiss, Z. Ernst-Moritz-Arndt-Univ. Greifswald, Math.-nat.wiss. Reihe 35, 39-44 (1986) 4, Pharmazie 39, H.10, 713 (1984), Pharmazie 87, H.12, 858-861 (1982), Neuroscience Letters 107, 327-330 (1989), PCT patent application International Publication Number WO 89/03818, and Khim.-Farm.zh. 23(11), 1349-1352 (1989), that certain of the chemical entities comprised within the scope of method of treatment according to the present invention are known to possess biological activity.